Mount for electron discharge devices



Sept. 18, 1934. D, Y SMITH 1,974,086

I MOUNT FOB ELECTRON DISCHARGE DEVICES I Filed Feb. 2, 1934 G IIVVEWTO"? DOUGLAS Y. SMITH 6 v /remark Patented Sept. 18, 1934 PATENT OFFICE MOUNT FOR ELECTRON DISCHARGE DEVICES Douglas Y. Smith, East Orange, N. .L, assignor to Radio Corporation of America, a corporation of Delaware Application February 2, 1934, Serial No. 709,433

- Claims. (Cl. 25027.5)

My invention relates to electron discharge de vices and more particularly to improved means for firmly and accurately'positioning the electrodes with respect to each other within the .5 envelope of the electron discharge device.

' In modern tubes such as. a tube having the dome type bulb the electrodes of the mount are held in position by a mica spacer having small apertures through which the end of the cathode '10 and the ends of the side rods of the various electrodes extend to rigidly position the electrodes with respect to each other within the bulb. In assembling tubes the numerous side rods of the electrodes are manually threaded in- 1 to small holes in the mica spacer. When the number of side rods is large this threading is tedious and difficult, and the necessary fingering of the side rods in forcing them into the holes in the spacer frequently bends the elementsout of .29 shape and damages them. Furthermore, the

threading operation usually requires nearly one half of the total time required to assemble the amount.

The principal object of my invention is to provide improved means for firmly and accurately positioning the electrodes of an electron discharge device with respect to each other Within the envelope to facilitate assembly of the electrode mount, and for substantially eliminating the damage to the delicate parts of the mount which frequently attends assembly of mounts constructed in the usual way.

The novel features which I believe to be characteristic of my invention are set forth with .3 particularity in the appended claims but the invention itself will best be understood by reference to the following description taken in connection with the accompanying drawing in which:

Figure 1 is a View in perspective and partly broken away of an electron discharge device embodying one form of my invention.

Figure 2 is an enlarged plan view of the mica spacer shown in Figure 1 and made in accordance with my invention.

Figure 3 is an enlarged perspective view of a portion of the mount shown in Figure 1 and showing a pair of mica spacers used in accordance with my invention.

The electron discharge device shown in Figure 1 has the usual base 10 on a dome type bulb 11 provided with the top cap 12 and the usual mount designated generally by 13. Extending from the top of the mount is the cathode sleeve 5 14, the side rods 15 of the various control grids (not shown) and the side rods 16 of the anode, one of the side rods 15, usually that of the control grid, being connected to the cap 12 at the top of the envelope 11.

In accordance with my invention there is supported at the top of the anode and secured to the anode side rods 16 by metal straps 19 the mica spacers 20 and 21, shown in more detail in Figures 2 and 3, and preferably semi-circular, as shown in Figure 2. Each spacer has two holes 22, into which the anode side rods 16 extend when the mica spacer is mounted on the anode, and also has along its flat edge a plurality of teeth 23 spaced to provide between them notches or slots into which the cathode 14 and side rods 15 fit rather snugly. To firmly and resiliently center the mount in the bulb resilient fingers 24 may be provided on the rim of the spacer to engage the inner wall of the dome of the bulb.

The method of mounting and locking the mica spacers on the mount is best shown in Figure 3. In assembling the mount the lower spacer 201s put on the plate side rods, which extend through the openings 22, and the cath ode sleeve and the various side rods slid sidewise into the slots between the teeth 23. The upper mica spacer 21 is then put in place on the anode side rods 16, with its toothed edge overlapping the toothed edge of the lower spacer 20, and with the teeth of the two spacers superposed, as shown in Figure 3. The two mica spacers are then locked in assembled position by welding the straps 19 to the anode side rods 16. Each spacer then acts as an insulating member for closing the ends of the slots in the other spacer to lock the electrodes in the slots. In this way I obtain a firm and rigid assembly, threading is eliminated and the cathode together with the anode and grid side rods are locked in the notches between the two overlapping spacers. While the upper spacer 21 is shown as of the same shape as the lower spacer 20, it need not be provided with teeth or slots, but may have merely a straight edge overlapping the teeth on the lower mica, to close the end of the slots and so look the side rods in place.

Another advantage of a mica spacer made :in accordance with my invention is that it can be readily slipped into place intermediate the units of a multi unit tube to space the various electrodes, it being understood that slots would have to be provided for all of the side rods including those on the anode.

While I have indicated the preferred embodiments of my invention of which I am now aware and have also indicated only one specific application for which my invention may be employed, it will be apparent that my invention is by no means limited to the exact forms illustrated or the use indicated, but that many. variations may be made inthe particular structure used and the purpose for which it is employed without departing from the scope of my invention as set forth in the appended claims.

What I claim as new is:

1. An electron discharge device havingan envelope, a mount within said envelope andcomprising a plurality of electrodes having side rods, an insulating spacer having an. edge provided with a plurality of slots, said side rods being received in said slots to space said electrodes in fixed relation with respect to each other and an insulating member cooperating with said spacer for closing the ends of said slots to lock said side rods in said slots.

2. An electron discharge device having an envelope, amount within said. envelope and com.-

prising a plurality of electrodes having side rods, an insulating spacer having an edge provided with slots for receiving the ends of said side rods, a second insulating spacer having an edge provided with slots in registry with the slots in said first spacer, said spacers being positioned to lock said siderods between said spacers within said slots.

3.; An electron discharge device having an envelope, a mount within saidenvclope comprising a'plurality of electrodes having side rods with their ends in alignment, a pair of substantially semi-circular insulating spacers mounted perpendicularly to said side rods and having slots along their straight edges for receiving the ends of said side rods within the slots, said spacers being positioned with respect to each other to form a substantially circular spacer having along a diameter apertures in which the siderods are locked in position.

straight edge having slots in registry with the slots onsaid first spacer in which the rest of the side rods are received, said spacers being secured to said end side rods to lock the side rods in the slots between said spacers.

5. An electron discharge device having an envelope, a mount within said envelope comprising a plurality of electrodes having side rods with their ends in alignment, a flat semi-circular insulating spacer positioned on one side of, and perpendicular to, said side rods and provided with apertures in which the end side rods are received and a straight edge having slots in which the; remainder of the side rods are received, a second semi-circular fiat insulating spacer positioned on the other side of, and perpendicular to, said side rods above said first spacer and in contact therewith and having apertures in which the end side rods are received and a straight edge having slots in registry with the slots of said first spacer in which the remainder of the side rods are received said spacers being secured to said end side rods to lock the side rods between them in the slots, and resilient fingers on the rims of said semi-circular spacers to resiliently position the electrode'mount Within the envelope.

? DOUGLAS Y. SMITH.

' ito iss 

